It has been known for some time that some species of the genus Ascochyta produce different metabolites exhibiting biological activity, in particular as phytotoxins. Examples thereof are e.g. an isoqinoline alkaloid, chrysantone, isolated from Ascochyta chrysanthemi (Phytochemistry, 28(3): 923-927, 1989), which is a phytotoxin, and which also exhibits antibacterial and weak antifungal activity. Ascotoxin (Decumbin) produced by A. imperfecta (Y. Suzuki, H. Tanake, H. Aoki and T. Tamura, Agric. Biol. Chem. 1970, 34, 395), is a strong plant pathogen with a phytotoxic activity exhibiting a strong inhibition of the growth of lucerne and rape. Cytochalasin A and B produced by A. heteromorpha (J. Natural Products, 50 (5): 989-998, 1987) are well known myco- and phytotoxins belonging to the cytochalasins a class of mold metabolites exhibiting various biological effects.
Ascochyta metabolites having the general formula (I) ##STR2## wherein R.sup.1 is independently hydrogen, hydroxy, alkyl with 1 to 6 carbon atoms, acyloxy groups with 1 to 6 carbon atoms, alkyloxy with 1 to 6 carbon atoms, or from 1 to 5 sugar moieties; and R.sup.2 is independently hydrogen, or alkyl with 1 to 6 carbon atoms, has been described in U.S. Ser. No. 08/095,785, the contents of which are incorporated herein by reference. These compounds are disclosed as exhibiting strong antifungal activity without phytotoxic activity, and are proposed for use in treatment of fungal plant diseases. It has now been determined, however, that compounds of this general formula also have a pharmaceutical utility, in that they show activity in inhibiting Tissue Factor Pathway Inhibitor(TFPI), and therefore can be used in reducing coagulation time in medical conditions which are characterized by excess or uncontrolled bleeding.